Video conferencing is the discussion between two or more people who are at different sites but can see and hear each other using telecommunications means. A telecommunication network carries pictures and sound such that conferences can take place across the world within a virtual space. For example, a point-to-point (two-person) video conferencing system works much like a video telephone. Each participant has a video camera, microphone, and speakers mounted on his or her communication device. As the two participants speak to one another, their voices are carried over the network and delivered to the other's speakers, and whatever images appear in front of the video camera appear in a window on the other participant's monitor.
Multi-point videoconferencing allows two, three, or more participants to sit in a virtual conference room and communicate as if they were sitting right next to each other. Videoconferencing will be one of the fastest-growing segments of the telecommunication industry.
The key to defining virtual reality in terms of human experience rather than technological hardware is the concept of presence. Presence can be thought of as the experience of one's physical environment; it refers not to one's surroundings as they exist in the physical world, but to the perception of those surroundings as mediated by both automatic and controlled mental processes. Presence is defined as the sense of being in an environment.
Many perceptual factors contribute to generating this sense, including input from some or all sensory channels, as well as more mindful attentional, perceptual, and other mental processes that assimilate incoming sensory data with current concerns and past experiences. Presence is closely related to the phenomenon of distal attribution or externalization, which refer to the referencing of our perceptions to an external space beyond the limits of the sensory organs themselves.
In unmediated perception, presence is taken for granted. However, when perception is mediated by a communication technology, one is forced to perceive two separate environments simultaneously: the physical environment in which one is actually present, and the environment presented via the medium. The term “telepresence” is used to describe the precedence of the latter experience in favor of the former; that is, telepresence is the extent to which one feels present in the mediated environment, rather than in the immediate physical environment.
Telepresence is defined as the experience of presence in an environment by means of a communication medium. In other words, “presence” refers to the natural perception of an environment, and “telepresence” refers to the mediated perception of an environment. This environment can be either a temporally or spatially distant “real” environment, for instance a distant space viewed through a video camera.
Improved video conferences will approximate telepresence, where (transparent) telepresence is understood as the experience of being fully present at a live real world location remote from one's own physical location. Someone experiencing transparent telepresence would therefore be able to behave, and receive stimuli, as though at the remote site. The resulting vicarious interactive participation in activities, and the carrying out of physical work, will bring benefits to a wide range of users.
U.S. Pat. No. 5,872,923 discloses a video conferencing system, wherein multiple parties at different locations can view, and modify, a common image on their computer displays. The invention also provides a video camera at each computer, which takes a video picture of each party. The invention distributes data to all computers involved in the conference from which each computer can generate a display containing the common image, the modifications, and the video pictures. At each site a facet of the environment is presented—a fractal partial communication space cramped mono-perspective impression.
The video conferencing apparatus disclosed in U.S. Pat. No. 6,330,022 supports a video conference including a processor/server, a conference bridge and a network of terminals, where each terminal equipped with at least a video camera, display and a user input device such as a mouse. A user may select a conference context including a conference location, type (setting) and purpose that may be different from the selection of another conferee. The user may select a conference location and type, view a conference according to a default selection or design their own location and type in advance of the conference. At the conference bridge, each conferee that joins a videoconference is assigned a position at a conference setting of their selected context, for example, a round table generated as a video graphic. At each terminal, a signal is either received or generated for display such that each conference participant is able to view all other participant conferees according to the assigned position arrangement within the context selected by the conferee. An audio signal can also be generated according to the assigned positions of the conferees that can be heard on 3D or stereo speakers in such a way as to relate to the assigned positions around the virtual conference setting.